Weighing devices

ABSTRACT

A weighing device ( 10 ) for providing a indication of the weight of a piece of luggage ( 5 ), the device comprising load bearing means ( 1 ) adapted to be placed on or form part of the carry means of the piece of luggage (H) and indicator means ( 19 ) associated with the load bearing means whereby when the luggage is lifted by the carry means (H), the load bearing means is subjected to the mass of the piece of luggage and the indicator means provides an indication of the weight of the piece of luggage.

FIELD OF THE INVENTION

This invention relates to weighing devices and in particular relates todevices that provide a ready indication of the weight of a piece ofluggage.

BACKGROUND OF THE INVENTION

Commercial aircraft have to place strict controls on the amount andweight of luggage that passengers carry on the aircraft. Tourists andinternational travelers often experience difficulties in ascertainingthe weight of their luggage and this can result in fines and surchargesfor being overweight. Whilst the check-in counters have scales thataccurately weigh luggage it is often then too late for a passenger tore-organise his or her luggage. What is needed and what is apparentlyabsent from the marketplace today is a simple means of providing anindication of the weight of a piece of luggage so that passengers candetermine the weight of the luggage before they reach the airport.

The issue of overweight luggage also has serious ramifications withregard to health and safety considerations. Heavy suitcases, rucksacksor satchels can cause serious spinal injuries. Research has indicatedthat children, and/or adults, should not over lengthy periods transportmore than 10% of their weight. In Australia there is a common practicefor school children to carry their text books, exercise books and evenlaptops in satchels or rucksacks. Often very small and frail childrenend up carrying loads far in excess of those recommended by the medicalprofession. Parents and staff of schools and other educationalestablishments need a ready indication of when a child is lifting ortransporting overweight luggage.

It is these needs that have brought about the present invention.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided aweighing device for providing a ready indication of the weight of apiece of luggage comprising load bearing means adapted to be placedthrough a carry handle of the piece of luggage and indicator meansassociated with the load bearing means whereby when the luggage islifted via the load bearing means or carry handle the load bearing meansis subjected to the mass of the piece of luggage and the indicator meansprovides an indication if a predetermined threshold mass has beenexceeded.

According to a further aspect of the present invention there is provideda piece of luggage having a carry handle assembly comprising a handleconnected to the piece of luggage, a pressure plate under the handle, aload cell between the pressure plate and the handle and means to providean indication of weight coupled to the load cell wherein when the pieceof luggage is lifted by the handle, the weight of the piece of luggageis transmitted to the load cell by contact with the pressure plate.

DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample only with reference to the accompanying drawings in which:

FIG. 1 illustrates a first embodiment of a weighing device which isinserted under a handle of a suitcase;

FIG. 2 shows the device when placed under load;

FIGS. 3 a, 3 b and 3 c are side view of the device under varying loads;

FIG. 4 illustrates a second embodiment of a weighing device supported bya hand;

FIG. 5 shows the device of FIG. 4 when held under the handle of asuitcase to weigh the suitcase;

FIG. 6 illustrates a third embodiment in which a weighing device is alsosupported by a user's hand;

FIG. 7 shows the device of FIG. 6 when inserted under the handle of asuitcase to weigh the suitcase;

FIG. 8 illustrates a fourth embodiment in which a weighing device isincorporated into the handle of suitcase;

FIG. 9 is an exploded view of the handle assembly of FIG. 8;

FIGS. 10 a and 10 b are schematic side elevational views of the handleof FIG. 8 when free standing and under load;

FIG. 11 is an illustration of a variation of the fourth embodiment;

FIG. 12 is an exploded view of the handle assembly in accordance with afifth embodiment;

FIG. 13 is a perspective view of a school satchel or rucksackincorporating a weighting device of a sixth embodiment;

FIGS. 14 a, 14 b, and 14 c show the device of FIG. 13 in various loadedconfigurations;

FIGS. 15 a and 15 b are exploded views of the device in unloaded andloaded configurations;

FIGS. 16 a and 16 b are perspective views of a weighting device inaccordance with a seventh embodiment in a loaded and unloadedconfiguration; and

FIGS. 17 a, 17 b, and 17 c are exploded views of the device in anunloaded, partially loaded and fully loaded configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment of the weighing device 10 shown in FIGS. 1 to 3comprises an elongate flat strip 11 of sturdy yet flexible materialusually plastics or metal having a central waisted portion 12 withenlarged end portions 13 and 14 each containing apertures 16 and 17. Anupstanding flange 18 is attached to the underside of the central portionof the waisted portion. The flange has an upward projection 20 having acalibrated forward face 19.

To use the device to weigh suitcase S the elongate strip 11 is placedunder the handle H of the suitcase S as shown in FIGS. 1 and 3 a.

By gripping the strip 11 by pressing fingers through the apertures 16and 17 the suitcase S can be lifted via the strip 11. As shown in FIGS.2, 3 b and 3 c, the mass of the suitcase causes the ends 13, 14 to bendupwards against the calibrated scale 19 which then provides a readyindication of the weight of the suitcase S. It is envisaged that thecalibrated scale 19 would include prominent marks that show the weightlevels as determined by airlines for both economy and business classtravel. Once the adjacent edge of the elongate strip has moved past oneof these lines the user will be aware that the suitcase is above theprescribed limit.

FIG. 3 a shows the strip 11 carrying no load, FIG. 3 b shows a readyindication of a light load whilst FIG. 3 c illustrates the effect of aheavy load. The thickness and flexibility of the strip is selected toensure the regular degree of movement against the calibrated scale.

The device 10 is about the size of an airline ticket and thus takes upvery little room so that it can be simply carried in hand luggage.

Instead of the mechanical device described with reference to FIGS. 1 and3, it is understood that the strip 11 could carry suitably positionedstrain gauges which would provide an electrical signal that could becorrelated to the weight to which the strip is subjected. The strip 11could also include a pressure sensitive chamber positioned directlyunder the handle to absorb the mass of the suitcase. The chamber couldinclude a chemical substance that changes colour under load so that achange to a selected colour would indicate that the weight of the pieceof luggage has exceeded a particular threshold.

It is understood that the chemical make-up of pressure sensitive pads orchemical substances that change colour under load would be known tothose skilled in the art.

In the second and third embodiments shown in FIGS. 4 to 7, the weighingdevice 30 is handheld and is in the form of a substantially flat creditcard shaped unit. The unit incorporates a sensor panel 31 on its uppersurface that senses downward pressure on the panel. The panelincorporates a load cell that is coupled to a liquid-crystal display(LCD) 32 and a suitable battery power source. The load cell senses thepressure on the sensor panel and converts the pressure to an indicationof weight.

In the embodiment shown in FIGS. 6 and 7, the device is placed on thepalm of a hand as shown in FIG. 6. The hand is then placed under thehandle 4 of the suitcase S as shown in FIG. 7 and the suitcase is liftedso that the weight of the suitcase presses down on the sensor panel 31on the upper surface of the device. This pressure is then transmitted asa weight on the liquid crystal display 32. In the embodiment shown inFIGS. 4 and 5, instead of a liquid crystal display a series of lights33, 34, 35, 36 representing recommended weights such as 20 kg, 30 kg, 40kg or 50 kg are provided. The lights are preferably light emittingdiodes. When the device is slid under the handle as shown in FIG. 5, theappropriate light 34 is illuminated showing that the suitcase is atleast as shown in FIG. 5 30 kg. Alternatively, the 20 kg, 40 kg or 50 kglights 33, 35 or 36 can illuminate. The device 30 thus provides a readyand simple means of showing that a predetermined weight has beenexceeded. The device of both of these embodiments is very small, runs ona small watch battery and takes up very little space. It is understoodthat the pressure sensitive panel would be one of a number ofproprietary items that provide an electrical signal that is proportionalto pressure.

In the fourth and fifth embodiments shown in FIGS. 8 to 12, a weighingdevice 40 is incorporated into the handle 4 of the suitcases.

In the exploded view of FIG. 9, the handle assembly 40 comprises anupper housing 41 with an aperture 42. The housing is of an arcuate shapeand supports end portions 43, 44. The housing 41 is arranged to containa circuit board assembly 45 that includes a pressure sensitive mechanism46 and a liquid crystal readout 47. The assembly would also incorporatea battery to power the weighing device. The assembly terminates on theunderside with an arcuate displaceable pressure plate 48 that has acentral spigot 49 that rides on the pressure sensitive mechanism 46 ofthe circuit board 45. As shown in FIGS. 10 a and 10 b, the pressureplate 48 is pulled up into the assembly 40 against the pressuresensitive plate 46 as the handle H is gripped and the suitcase S liftedoff the ground. In this way, the weight of the suitcase S is transferredthrough the pressure sensitive plate to be recorded and indicated at theLCD readout 47. The final assembly of the handle is shown in FIG. 8 fromwhich it can be seen that the weighing device 40 is elegantly integratedinto the design of a suitcase S so that travellers can buy a range ofluggage each of which has its own built-in weighing device.

The assembly is moulded in plastics and is light and substantially thesame size as a conventional handle. In order to prolong the life of thebatteries that power the unit, it is understood that an on/off switchmay be provided somewhere on the handle to prevent use of the assemblywhenever the suitcase is carried.

In the embodiment shown in FIG. 11, a very similar device 40 isincorporated except in this case instead of a single LCD readout 47,four space lights 50, 51, 52, 53 are provided across the top of thehandle H, each light representing a threshold weight such as 10 kg, 20kg, 30 kg or 40 kg.

The load cell between the pressure plate 48 and the top of the handle 41would send electrical signal to each light in dependence on the weightof the suitcase.

In the embodiment shown in FIG. 12, the load cell is replaced by acoloured indicator 60 which locates in an aperture 61 in the externalcover 62 of the handle. The coloured indicator 60 is mounted on asupport plate 63 and a pressure plate 64 has a single upstanding spigot65 that acts against the underside of the coloured indicator 60 in thesame manner as the spigot acts on the load cell in the embodiment ofFIGS. 9 to 11. However, in this embodiment the coloured indicator is inthe form of a disc that changes colour under pressure and thus changescolour proportional to the weight of the suitcase. As the pressureincreases the colour of the disc can be calibrated so that a change to aparticular colour indicates that the luggage weighs more than aparticular threshold.

Other embodiments not illustrated also incorporate the use of pressuresensitive chemicals that change colour in dependence on pressure. A cardor plastics sheet could be provided with bands of such chemicals. Thecard or sheet could be placed under the handle of the suitcase and thesuitcase lifted via the card or sheet. In this way, the weight of thesuitcase would place pressure on the chemical laminate causing a changeof colour and the colour would be calibrated to indicate whether airlinethresholds have been exceeded.

The invention is also applicable to rucksacks or satchels especiallythose used by school children to carry their text books and laptops. Thecommon practice of school children transporting excessively heavy loadsin satchels and/or rucksacks is well known. The embodiments of FIGS. 13to 17 provide a means that provides a ready indication that the load istoo great.

The sixth embodiment is illustrated in FIGS. 13 to 15. FIG. 13 shows arucksack R that is supported by parallel shoulder straps 70, 71 and awaist strap 72. As shown in FIGS. 15 a and 15 b, a resilient strip 75 ofrubber or plastics is secured by stitching, welding or riveting inparallel along a length 76 of the strap 70 or 71 with the strap as shownin FIG. 15 a, when unloaded, being in an unstressed slightly undulatingconfiguration. When the strap 70 or 71 is placed under load theresilient member 75 stretches to absorb the slack in the strap as shownin FIG. 15 b. A cover 77, 78 is supported on each end of the resilientmember 75 to assume a substantially closed configuration when the strap70, 71 is not under load as shown in FIG. 14 a, a partially expandedconfiguration when the strap 70, 71 is under partial load as shown inFIG. 14 b, and a fully expanded configuration when the strap 70, 71 isunder maximum load shown in FIG. 14 c. The resilient strap 75 would becoloured or otherwised marked as shown in the drawings so that as theload increases there is a ready visual indication of that load whichcould be either caused by a flash of colour or a visible scale orwarning sign that would warn a parent or teacher that the rucksack iscarrying excessive weight. Thus, for instance, the resilient member 75would be calibrated so that the desired comfortable weight as shown inFIG. 14 a, a slightly excessive weight, whilst still permissible, isshown in FIG. 14 b and impermissible excessive weight is shown in FIG.14 c. This feature could be on a single strap 70 or preferably on bothstraps 70, 71 as shown in the view of the rucksack R in FIG. 13.

In another embodiment on the same theme shown in FIGS. 16 and 17, aconcertina enclosure 80 having a series of parallel bellows 81 isattached to the strap 70 or 71 to assume, in an unloaded configuration,the view in FIG. 16 a or 17 a that is with the strap in an unstressedand undulating configuration. As a load is placed on the strap theelongate strap expands the bellows 81 to assume a differentconfiguration shown in FIG. 17 b. When fully under load the strapassumes the stretched configuration shown in FIG. 17 c which furtherexpands the concertina bellows 81 to assume the profile shown in FIG. 16b.

The bellows 81 can be painted in a manner that vivid colours only becomevisible as the bellows expand so that in the fully expanded view shownin FIG. 17 a there may be a large red flash along the length of thebellows which would provide a ready indication that the strap 70, 71 isunder excessive load.

It is understood that other more sophisticated means can be incorporatedinto devices of the kind described above such as the use of straingauges or load cells and indicator means that provide coloured lights ordigital indication of the exact weight of a rucksack or satchel.However, a simple mechanical mechanism with a visual indicator is viewedas the most practical and cost effect means of solving what is becomingan increasing problem that can result in serious spinal injuries toyoung children.

1. A weighing device for providing a ready indication of the weight of apiece of luggage, the device comprising load bearing means adapted to beplaced on or form part of the carry means of the piece of luggage andindicator means associated with the load bearing means whereby when theluggage is lifted by the carry means, the load bearing means issubjected to the mass of the piece of luggage and the indicator meansprovides an indication of the weight of the piece of luggage.
 2. Theweighing device according to claim 1 wherein the load bearing means isan elongate strip of flexible plastics or metal.
 3. The weighing deviceaccording to claim 2 wherein the load bearing means has a load bearingcentre portion between ends whereby when the piece of luggage is liftedby gripping the ends the strip flexes due to load on the centre portion.4. The weighing device according to claim 3 wherein each end has a holewhich defines a finger grip enabling the strip to be picked up.
 5. Theweighing device according to claim 3 wherein the indicator means is acalibrated scale fixed to the centre portion adjacent one lateral edgeof the strip whereby that edge moves relative to the scale as the stripflexes under load.
 6. The weighing device according to claim 1 whereinthe load bearing means is a load cell positioned across a housingadapted to be held in the palm of the hand whereby the device, in use,is positioned between the palm of the hand and the handle of the pieceof luggage so that the weight of the piece of luggage is sensed by theload cell as the hand lifts the luggage via the handle.
 7. The weighingdevice according to claim 6 wherein the housing supports the indicatormeans which provides a visual indication of the weight of the luggage.8. The weighing device according to claim 7 wherein the indicator meanscomprises a strip of coloured panels which light up proportional to theweight of the piece of luggage.
 9. The weighing device according toclaim 7 wherein the indicator means is a coloured panel that changescolour in dependence of the weight of the piece of luggage.
 10. Theweighing device according to claim 7 wherein the housing isapproximately the same dimensions as a credit card.
 11. The weighingdevice according to claim 7 wherein the load cell is battery powered andthe battery is located in the housing.
 12. The weighing device accordingto claim 7 wherein the indicator means is a liquid crystal displaycoupled to the load cell to provide a digital indication of the weightof the piece of luggage.
 13. A handle assembly for a piece of luggagecomprising a handle adapted to be connected to the piece of luggage, apressure plate under the handle, a load cell between the pressure plateand the handle and indicator means coupled to the load cell to providean indication of weight subjected to the load cell when the piece ofluggage is lifted by the handle.
 14. The handle assembly according toclaim 13 wherein the handle comprises an arcuate housing that is securedto either end of the piece of luggage, the housing supporting the loadcell coupled to the indicator means that is visible from above thehandle, the pressure plate being supported by the housing under the loadcell whereby when the handle assembly is picked up the weight of thepiece of luggage is transferred to the load cell via the pressure plateand the indicator means provides visual indication of the weight. 15.The handle assembly according to claim 14 wherein the indicator means isa liquid crystal display.
 16. The handle assembly according to claim 14wherein the indicator means is an array of lights which light upproportionally to the weight of the luggage.
 17. The weighing deviceaccording to claim 1 wherein the carry means is a shoulder strap of arucksack or satchel and the load bearing means is either an elasticportion of the strap or an elastic strap attached parallel to anundulating portion of the strap.
 18. The weighing device according toclaim 17 wherein the indicator means constitutes part of the elasticsstrip or elastic portion of the strap that becomes exposed to provide avisual indication of the load bearing means being stretched under load.19. The weighing device according to either claim 17 wherein the elasticportion is covered from each end, the cover separating under load toexpose the indicator means.
 20. The weighing device according to claim17 wherein the elastics strip comprises concertina bellows secured tosurround an undulating portion of the strap whereby the externalconfiguration of the bellows change as the strip stretches under load.21. The weighing device according to claim 20 wherein the bellows arecoloured in a manner that the colours are exposed as the bellows changeconfiguration on stretching.